Heating furnace



June 16, 1925. 1,542,193

F. A WALD HEATING FURNACE 2 Sheets-Sheet l.

NESSE Q Mum/ F. A Wa d) June 16, 1925.

' 1,542,193 F. A. WALD 111mm; FURNACE Filed llay 1923 V 2 Sh'eets-Sheet 2 WITNESSES "WE/V701? F. A .Wald,

A TTORNE Y8 structions, combinations and mode of opera- 7 Patented dune '16, 1925.

umren sr'rss tenses FRANK A. VIALD, OF CAMP HILL, PENNSYLVANIA.

HEATING FURNACE.

Application filed. May 8,

To all whom it may concern:

Be it known that I, FRANK A. l VALD, a citizen of the United States, and a resident of Camp Hill, inthe county of Cumberland and State of Pennsylvania, have invented certain new and useful Improvements in Heating Furnaces, of which thefollowing is a specification.

My invention relates to improvements in heating furnaces and it consists of the con tion herein described and claimed.

An object of the invention is to provide a heating furnace having an arrangement of deflectors and baflies designed to prevent the expansion and escapeof gases of combustion before consumption, thereby deriving a greater heat value from the fuel.

A further object of the invention is to provide arches and radiating deflectors in a heating furnace for the purposeof confining the gases in a smaller space than usual while in the process of combustion, thereby providing a hotter fire zone; A further object of the invention is to provide a heating furnace having arches disposed overthe fire in such a manner as to lengthen the passage for the products of combustion toward the flue outlet of the furnace.

A further object of the invention is to provide a heating furnace having a plurality of arc hes for the aurpose last described, having means by whic they may be adjusted both in respect to each other and in respect to the fire.

Another object of the invention is to. provide arches for the purpose described which are made in sections of convenient size to permit introductionat the fire door of the furnace, thereby making it possible to make replacements without taking the entire furnace apart. 7

A further object of the invention is to provide a heating furnace having a plurality of deflectors adapted to surround the fire, one of these being furnished with fines for supplying the fire with air from outside ofv the furnace. i

Other objects and advantages will ap- 1923. Serial No. 637,506.

pear in the following specification, reference being had to the accompanying drawings, in which:

Figure 1 is afront elevation of aheating furnace, portions being broken away to show parts of the arches and deflectors on the inside,

furnace 1 of the sectional variety commonly used in houses. The furnace includes the fire door 2 and outlet flue 3. The furnace is water jacketed, and the so-called water legs 4 (Fig. 1) extend down well toward the bottom of the furnace so as to gain all possible advantage of the fire.

Grate bars 5 support the fire F. These bars, instead of being supported in the furnace in the customary manner, are supported by lugs 6 (Figs. 1 and 2) cast or otherwise affixed to rest bars26 which extend lengthwise of the furnace. These bars are primarily intended to support cast iron radiating deflectors 7 which also run lengthwise of the furnace. These deflectors are part of the invention.

The ends of the furnace are likewise fitted with cast iron deflectors 8 and 9 (Fig. 2); These, too,'are part of the invention. They are supported by rest bars 27 which run cross wise of the furnace.

The front deflector 8 should be out out where it crosses the opening of the fire door 2. The rear deflector 9 extends higher than the rest for the purpose of providinga more substantial back, and also to provide an ample surface to receive the bed of coals shou'ldthe firebe banked higher toward the rear'than the front. The upper edges 10 of the radiating deflector are beveled at an angle of approximately so that fuel will not lodge on the edges, and also provide approaches permitting the arches 11 and 12 to more readily enter the fire chamber when such adjustment is desired to be efiected.

The vertical meeting edges of the defiectors 7, 8 and 9 are beveled at an angle of 45, as shown for example at 13in Figure t in respect to the front and left side deflectors 8 and 7. The purpose of this arrangement is not only to make good corner oints but also to insure against the deflectors caving in upon the fire. The deflectors may simply be set in position in the furnace 1 and the contact of the beveled ends relied upon to keep them in the upright position.

Suspension rods 14 and 15 support the arches 11 and 12. These in turn are fastened to an equalizing bar 16 (Fig. 2), the fastening of the rods 14 being permanent but that of the rods 15 being adjustable. The rods 15 are flattened as shown and have a plurality of holes 17 drilled therein so that they may be hung at various places on the bolts 18. The adjustment of the arch 12 by means described, permits varying of the opening 19. Adjustments are made accordingly as furnace and coal conditions Vary. The size or adjustment of the open ing 19 between the arches 11 and 12 is governed to some extent by the quality of fuel and rate of combustiomand by suitably adjusting the radiating arches in respect to the side deflector plate it is possible to. reduce the draft in the gas outlet fine of the furnace to a minimum. It is by means of the usual damper in this line (not shown) that draft regulation is obtained.

Extending from the radiator deflector 9 is a plurality of air outlet nozzles 28 which have communication with a common distributing port 29 formed in the deflector. A passage 30 offers communication between the port 29 and a pipe 31 by which air is admitted to the port. There is a valve 32 at the end of this pipe. This valve has a port 33 across which a disk 34; (Fig. 5) is adapted to move. This disk has a corresponding port 85, the two being adapted to be moved into various degrees of registration so as to admit more or less warm air as desired. Only two ports 33 and are shown but obviously the port arrangement may be as desired.

The nozzles 28 are inclined at approximately 45 from the face of the deflector 9. The purpose of the nozzles is to direct warm air from the ash pit upon the fire especially after having put on fresh fuel. At such times, as well as at times when the fire is banked, the supply of air through the fuel; bed is insufiicientfor the combustion of gases which are distilled from fresh charges of fuel. Hence by admitting air over the fire through the radiator deflector plate 9 air will be heated to a temperature suitable for ignition of the gases and thus insuring perfect combustion.

The equalizing bar 16 is supported at the ends (or elsewhere if desired) by cables 20 and 21 which run over pulleys 22 and have common connection with the counterweight 23.

By merely pulling down or pushing up on the counterweight 23, the arches 11 and 12 are raised or lowered as may be desired. This particular mode of adjustment of the arches is desirable to compensate for any variation of the fire level. It is also necessary to raise the arches when adding fresh fuel at thefirc door 2.

The arches consist of flat slabs of a suitable refractory material. The necessity of ultimately replacing the arches is provided =4;-

for by making them in sections as shown in Figure 3. These sections are suitably fitted together at 24 and are furthermore bound together by suitable means 25 which may conveniently consist of a part of the The operation.

-The purpose of the radiating deflectors 7, S and 9 and of the refractory arches 11 and 12 is to retard the expansion and escape of the gases of combustion so that a more thorough consumption may take place and more of the heating value of the fuel derived therefrom. The arches 11 and 12 keep these gases throttled in a small space and hence a furnace constructed in accordance with the invention will have a hotter fire zone than one in which there is almost a direct path between the fire bed and the outlet flue.

The heat of the fire F penetrates the deflectors 7, 8 and 9 and the walls of the water legs l, and being more intense by virtue of the throttling action of the arches 11 and 12, will be very effective in heating the water. It is undesirable that the gases contact the heating surface of the boiler in the immediate vicinity of the fire and the deflectors therefore in a manner insulate the heater from direct radiation of the fire zone. The reason why it is undesirable for gases in the process of combustion to come into contact with the heating surfaces of the boiler is that a. temperature of 1500 F. is required to ignite the gases, and as the temperature of the boiler is no hotter than its heat distributing elements (which in a hot water boiler would be to 200 F. and for a steam or vapor ordinarily to 220 it can readily be seen that there are advantages in keeping the gases from con- Ill tacting with the heating surfaces before combustion is completed.

These advantages are greater with bituminous coal than with anthracite coal owing to -the fact that the volatile of bituminous coal is as high as 40% of its heat value. At a low rate of combustion, at which heating furnaces are usually operated, the average heat is hardly more than will merely distill gases from the fuel and hence there isa great waste. by virtue of the fact of the escape of these gases before combustion can take place.

j The arches 11 and12 above the fuel bed prevent gases from rising and expanding below ignition temperature.

The arches are so disposed that all gas is forced to pass toward the center of the furnace where, presumably, it is hottest. In ......using the to pass through the throat 19 between the arches, mixture with sufficient air occurs so that the combustion would be completed before the gases could come into contact with the heating surfaces of the boiler with the attendant. bad effect mentioned above.

It has been found in practice that the arrangement disclosed gives good results with the smaller sizes of anthracite coal, for example buckwheat and barley, and will also give good results with bituminous coal. It

is necessary to first raise the arches 11 and 12 before fuel can be thrown in at the fire door 2. This is simply done by pulling down on the counterweight 28.

After the fuel is thrown in and the fire properly leveled, the arches are again lowered by pushing up on the counterweight. The size of the opening 19 is adj usted for the particular kind of fuel in use. A change of fuel may require a change in the size o-fthe opening-19, and such change is made by removing the bolts 18 and bring others of the holes 17 in registration with the equalizing bar 16. The arches 11 and 12 are also adjusted up and down to suit the level of the fire bed. As mentioned before, the beveled approaches permit the arches 11 and 12 to enter the fire chamber more readily than if the inner surfaces of the deflectors were carried up straight. The air nozzles 28 are located sufficiently low down on the deflector 9 that the arch 12 will not touch even at the lowermost adjustment.

In respect to the operation of the nozzle 28 it may be added that upon placing a fresh charge of fuel into the fire the temperature in the fire chamber will naturally be lowered. This is attended by a reduction in pressure or a partial vacuum which will permit air and atmospheric pressure to flow from. the outside through the ports 33 and 35 and out at the nozzles 28 to the fire zone. As stated before, these nozzles discharge below the arch 12. Any gas leaving the fire prevent them zone under the arch 11 will get a supply of air from the nozzle end of the furnace in passing through the throat 19.

After the ignition of the fuel the ten-r perat-ure and pressure in the fire chamber will increase and to some extent balance with the outside air pressure in the pipe 31, thereby tending to stop the flow of air out of the sorts 33 and 85. The internal furnace pressure therefore in a measure automatically regulates the inflow of air. The purpose of directing the nozzles 28 at an angle is to p and the distributing ports 29 from being fouledby filling with ashes and fueh While the construction and arrangemen of the improved heating furnace as herein described and claimed, is that of a generally preferred form. obviously modifications and changes may be made without departing from the spirit of the invention or the scope of the claims.

I claim i 1. A heating furnace having a grate, a plurality of arches positioned above the grate, suspending means for the arches capable of adjustments to vary the space between the arches and the grate, and means permitting relative adjustments between the arches.

2. A heating furnace having a grate, a pair of arches in position above the grate one arch overlapping the other to provide an opening, and suspending means for the arches including means by which one arch may be varied in position in respect to the other to change the size of said opening.

3. A heating furnace having a grate, an arch disposed over the grate adjacent to the front of the furnace, an arch disposed over the grate adjacent to the back of the furnace andoverlapping the first arch to provide a forwardly extending passage, suspending means in engagement with the respective arches, means to which the suspending means I of the first arch. is fixed for support, means by whlch the suspending means of the sec- 011d arch 1s adjust-ably mounted on said support, and cables and a counterweight in connection with said suspending means permitting simultaneous adjustment of both arches in respect to the grate.

4. A heating furnace comprising portions containing a heat carrying element, deflector plates fitted inside of said portions, grate bars fitted inside of said deflectors, means by which said bars are supported thus defining a fire chamber, an arch positioned above the. grate, and suspending means for the arch capable of adjustment into and out of said deflectors to provide a cover at varying distances from the fire.

5. A heating furnace comprising portions containing a heat-carrying element, deflector plates fitted inside of said portions to partly insulate the fire from said portions, grate bars fitted inside of said deflectors, means for supporting the grate bars, a plurality of arches of which one overlaps the other but leaving a space for the passage of the prod ucts of combustion from the fire, means by which the arches are supported and are adjustable into and out of said deflectors to vary the space above the fire, and means by which one arch may be adjusted in respect to the other to vary the size of said passage.

6. A furnace having grate bars, deflector plates fitted inside of the furnace and having means by which said bars are supported said plates having inwardly beveled upper edges to prevent the lodgment of fuel, arches disposed above the grate bars, and'suspending means for the arches permitting vertical adjustments thereof in respect to the bars said beveled portions providing approaches assisting the'entrance of the arches inside of said plates.

7. A furnace having a grate for supporting the fire, deflectors surrounding the fire, elements which are adapted to be heated situated outside of said deflectors, and arches adjustable inside of said deflectors in respect to the fire being so arranged as to cause the gas to travel toward the center of the fire zone for thorough combustion before being permitted to reach said elements.

8. A furnace having a grate for supporting the fire, elements adapted to be heated, deflectors situated between the fire and said elements on all sides of the furnace the deflector at the rear being higher than the rest, said deflector having an air port formed therein, air nozzles extending from said rear deflector toward the fire bed, said nozzles communicating with said air port, means extending from said port under the grate and outside of the furnace to furnish air to said nozzles, and arches adapted to be so positioned in respect to the deflectors, fire and nozzles as to confine the gases and insure a thorough mingling with air so that thorough combustion occurs before the gases reach said elements.

FRANK A. WALD. 

